DBMS overview, RDBMS v/s DBMS, File system & DBMS

What is Database?

A Database is a collection of coherent meaningful data today, typically in a digital form, so that its content can easily be accessed managed & updated. 

The example of postal address would generally contain:

• Building name
• Street name 
• Flat No. 
• City 
• State 
• Pin code 
• Country etc. Thus the address book is a database and the postal address in the book, is the data that fills the database.

What is DBMS?

A DBMS is a software package with computer program that control the creation, maintenance & use of a database. It allows organization to conveniently develop databases for various applications by DBA (Data Base Administrator).

In general term, the system that manages the database can be said as DBMS.

What is RDBMS?

RDBMS is a DBMS that is based on relational model as introduced by Dr. Edger F.Codd. Strictly speaking it should always Codd`s 12 rules. It stores data in the form of related table. 

Difference b/w DBMS & RDBMS?

Difference b/w DBMS & traditional file system?

1. Inconsistency: In case of file system a particular data may be present in different files. Once user updates a file that updation may not be reflected to others files. It bring system in an inconsistent state. DBMS ensures that updation must be reflected to the whole system as & when it is necessary.


2. Redundancy: Earlier in the file system a particular data unnecessarily repeats in several file system which sometimes cost high to store the data in memory & its arises redundancy problem.Introduction to DBMS reduces unnecessarily repetition of data. So, it saves the cost of memory.


3. Difficulty in accessing data: In file system we need to access data by writing procedural language which makes our job tough. DBMS like oracle  provides SQL to fetch out data from database easily.


4. Integrity problem: File system could not ensures integrity due to lack of its architecture. The architecture of DBMS is such that its provide integrity of database by introducing the "key" concept.


5. Atomicity Problem: Database ensures that once a tuple (row) is updated & in the mid of the way if their is a power failure then either the whole row is updated or none of the attribute is updated. Unfortunately file system never ensures atomicity.   


6. Concurrent access anomalies:  Earlier in file system more than two users in a network cannot access a single file at a same time which slopped down the computation speed. DBMS introduced different logging protocol through which it ensures concurrent access of more than one user on a same database.


7. Security problem: Architecture  of DBMS is such that it allows user to stay in their own domain that is according to their right they are allowed to view only that part of database. While file system was not enforcing any security constarint.